Deposition of Organic Matter on Alpine Snow

Abstract

There is currently minimal research that investigates the deposition and re-volatilization of organic matter (OM) on snow. Understanding this balance for individual organic compounds has the potential to provide more additional valuable information about past and present atmosphere-biosphere interactions. OM captured in the blank canvas of snow can reflect corresponding signatures of atmospheric OM once their deposition and re-volatilization rates are known. Furthermore, understanding this link between organics in the atmosphere to those found in surface snow will allow for improved interpretations of OM that is eventually preserved in glacial ice. This research builds on a recent pilot study by Materić et al. (2019) which investigated the post-precipitation change of OM in surface snow near the Sonnblick Observatory in the Austrian Alps using thermal-desorption proton transfer reaction mass spectrometry (TD-PTR-MS). This research now widens this investigation with an array of surface snow samples taken every alternate day at the observatory and around the surrounding area. Each sample was analyzed using TD-PTR-MS with both filtered and unfiltered protocols to differentiate detected micro and nano scale particles. An assessment of the sample data shows a high correlation between the OM found at the observatory and surrounding sampling locations, as well as a positive detection of nanoplastics using a fingerprinting algorithm developed by Materić et al. (2020). PTR-MS measurements of atmospheric OM in conjunction with meteorological data also recorded at the observatory throughout the snow sampling period suggests a possible link between surface snow OM and a pollution event characterized by a shift in wind direction.